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Electron-Cloud Effects on Heavy-Ion Beams (open access)

Electron-Cloud Effects on Heavy-Ion Beams

Stray electrons can be introduced in positive-charge accelerators for heavy ion fusion (or other applications) as a result of ionization of ambient gas or gas released from walls due to halo-ion impact, or as a result of secondary-electron emission. We are developing a capability for self-consistent simulation of ion beams with the electron clouds they produce. We report on an ingredient in this capability, the effect of specified electron cloud distributions on the dynamics of a coasting ion beam. We consider here electron distributions with axially varying density, centroid location, or radial shape, and examine both random and sinusoidally varying perturbations. We find that amplitude variations are most effective in spoiling ion beam quality, though for sinusoidal variations which match the natural ion beam centroid oscillation or breathing mode frequencies, the centroid and shape perturbations can also be effective. We identify a possible instability associated with resonance with the beam-envelope ''breathing'' mode. One conclusion from this study is that heavy-ion beams are surprisingly robust to electron clouds, compared to a priori expectations.
Date: March 29, 2004
Creator: Azevedo, T; Friedman, A; Cohen, R & Vay, J
System: The UNT Digital Library
Waste Treatment Plant LAW Evaporation: Antifoam Performance (open access)

Waste Treatment Plant LAW Evaporation: Antifoam Performance

This report describes the work performed to determine the performance and fate of several commercial antifoams during evaporation of various simulants of Envelope A, B, and C mixed with simulated River Protection Project Waste Treatment Plant (RPP-WTP) recycle streams. Chemical and radiation stability of selected antifoams was also investigated.Contributors to this effort include: Illinois Institute of Technology (IIT), DOW Corning Analytical, and Savannah River Technology Center (SRTC).
Date: March 29, 2004
Creator: BAICH, MARKA
System: The UNT Digital Library
Field Demonstration of a Membrane Process to Recover Heavy Hydrocarbons and to Remove Water from Natural Gas (open access)

Field Demonstration of a Membrane Process to Recover Heavy Hydrocarbons and to Remove Water from Natural Gas

The objective of this project is to design, construct and field demonstrate a membrane system to recover natural gas liquids (NGL) and remove water from raw natural gas. An extended field test to demonstrate system performance under real-world conditions would convince industry users of the efficiency and reliability of the process. The system has been designed and fabricated by Membrane Technology and Research, Inc. (MTR) and will be installed and operated at British Petroleum (BP)-Amoco's Pascagoula, MS plant. The Gas Research Institute will partially support the field demonstration and BP-Amoco will help install the unit and provide onsite operators and utilities. The gas processed by the membrane system will meet pipeline specifications for dewpoint and BTU value and can be delivered without further treatment to the pipeline. Based on data from prior membrane module tests, the process is likely to be significantly less expensive than glycol dehydration followed by propane refrigeration, the principal competitive technology. At the end of this demonstration project the process will be ready for commercialization. The route to commercialization will be developed during this project and may involve collaboration with other companies already servicing the natural gas processing industry.
Date: September 29, 2004
Creator: Baker, R.; Hofmann, T. & Lokhandwala, K. A.
System: The UNT Digital Library
A finite difference model used to predict the consolidation of a ceramic waste form produced from the electrometallurgical treatment of spent nuclear fuel. (open access)

A finite difference model used to predict the consolidation of a ceramic waste form produced from the electrometallurgical treatment of spent nuclear fuel.

Argonne National Laboratory (ANL) has developed a process to immobilize waste salt containing fission products, uranium, and transuranic elements as chlorides in a glass-bonded ceramic waste form. This salt was generated in the electrorefining operation used in the electrometallurgical treatment of spent Experimental Breeder Reactor-II (EBR-II) fuel. The ceramic waste process culminates with an elevated temperature operation. The processing conditions used by the furnace, for demonstration scale and production scale operations, are to be developed at Argonne National Laboratory-West (ANL-West). To assist in selecting the processing conditions of the furnace and to reduce the number of costly experiments, a finite difference model was developed to predict the consolidation of the ceramic waste. The model accurately predicted the heating as well as the bulk density of the ceramic waste form. The methodology used to develop the computer model and a comparison of the analysis to experimental data is presented.
Date: March 29, 2004
Creator: Bateman, K. J. & Capson, D. D.
System: The UNT Digital Library
Heat Pump Water Heater Durabliltiy Testing - Phase II (open access)

Heat Pump Water Heater Durabliltiy Testing - Phase II

Ten heat pump water heaters (HPWH) were placed in an environmentally controlled test facility and run through a durability test program of approximately 7300 duty cycles (actual cycles accumulated ranged from 6640 to 8324 for the ten units). Five of the units were upgraded integral types (HPWH mounted on storage tank, no pump) from the same manufacturer as those tested in our first durability program in 2001 (Baxter and Linkous, 2002). The other five were ''add-on'' type units (HPWH with circulation pump plumbed to a separate storage tank) from another manufacturer. This durability test was designed to represent approximately 7-10 years of normal operation to meet the hot water needs of a residence. The integral units operated without incident apart from two control board failures. Both of these were caused by inadvertent exposure to very hot and humid (>135 F dry bulb and >120 F dew point) conditions that occurred due to a test loop failure. It is not likely that any residential water heater would be installed where such conditions were expected so these failures are not considered a long-term reliability concern. Two of the integral HPWHs featured a condensate management system (CMS) option that effectively eliminated any need …
Date: May 29, 2004
Creator: Baxter, VAND.
System: The UNT Digital Library
Intelligence Reform and Terrorism Prevention Act of 2004: "Lone Wolf" Amendment to the Foreign Intelligence Surveillance Act (open access)

Intelligence Reform and Terrorism Prevention Act of 2004: "Lone Wolf" Amendment to the Foreign Intelligence Surveillance Act

This report discusses the "Lone Wolf" Amendment to the Foreign Intelligence Surveillance Act (FISA), which designates non-United States persons who engage in or prepare to commit international terrorism as "agents of a foreign power".
Date: December 29, 2004
Creator: Bazan, Elizabeth B.
System: The UNT Digital Library
Environmental Protection Agency: Appropriations for FY2005 (open access)

Environmental Protection Agency: Appropriations for FY2005

The President signed the Consolidated Appropriations Act for FY2005 on December 8, 2004. The law provides funding for numerous federal agencies, including $8.09 billion for the Environmental Protection Agency, subject to an across-the-board rescission of 0.8%. The final appropriations is more than the Administration's request of $7.79 billion, but is less than the FY2004 appropriation of $8.37 billion. This report contains information on the final action on FY2005 appropriations for the EPA.
Date: December 29, 2004
Creator: Bearden, David & Esworthy, Robert
System: The UNT Digital Library
Farm and Food Support Under USDA's Section 32 Program (open access)

Farm and Food Support Under USDA's Section 32 Program

This report discusses “Section 32”, which is a permanent appropriation that since 1935 has earmarked the equivalent of 30% of annual customs receipts to support the farm sector through a variety of activities. Today, most of this appropriation (now approximately $6.5 billion yearly) is transferred to the U.S. Department of Agriculture (USDA) account that funds child nutrition programs.
Date: September 29, 2004
Creator: Becker, Geoffrey S.
System: The UNT Digital Library
Recent Site-Wide Transport Modeling Related to the Carbon Tetrachloride Plume at the Hanford Site (open access)

Recent Site-Wide Transport Modeling Related to the Carbon Tetrachloride Plume at the Hanford Site

Carbon tetrachloride transport in the unconfined aquifer system at the Hanford Site has been the subject of follow-on studies since the Carbon Tetrachloride Innovative Treatment Remediation Demonstration (ITRD) Program was completed in FY 2002. These scoping analyses were undertaken to provide support for strategic planning and guidance for the more robust modeling needed to obtain a final record of decision (ROD) for the carbon tetrachloride plume in the 200 West Area. This report documents the technical approach and the results of these follow-on, site-wide scale-modeling efforts. The existing site-wide groundwater model was used in this effort. The work extended that performed as part of the ITRD modeling study in which a 200 West Area scale submodel was developed to examine arrival concentrations at an arbitrary boundary between the 200 E and 200 W areas. These scoping analyses extended the analysis to predict the arrival of the carbon tetrachloride plume at the Columbia River. The results of these analyses illustrate the importance of developing field-scale estimates of natural attenuation parameters, abiotic degradation rate and soil/water equilibrium sorption coefficient, for carbon tetrachloride. With these parameters set to zero, carbon tetrachloride concentrations will exceed the compliance limit of 5 {micro}g/L outside the 200 …
Date: September 29, 2004
Creator: Bergeron, Marcel P. & Cole, C R.
System: The UNT Digital Library
Savannah River Ecology Laboratory 2004 Annual Technical Progress Report (open access)

Savannah River Ecology Laboratory 2004 Annual Technical Progress Report

2004 annual report of research conducted by the Savannah River Ecology Laboratory, a research unit of The University of Georgia operating on the Savannah River Site in Aiken, South Carolina
Date: July 29, 2004
Creator: Bertsch, Paul M.
System: The UNT Digital Library
Proposals for Intelligence Reorganization, 1949-2004 (open access)

Proposals for Intelligence Reorganization, 1949-2004

None
Date: July 29, 2004
Creator: Best, Richard A., Jr.
System: The UNT Digital Library
Drift-Scale Coupled Processes (DST and TH Seepage) Models (open access)

Drift-Scale Coupled Processes (DST and TH Seepage) Models

The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces …
Date: September 29, 2004
Creator: Birkholzer, J. & Mukhopadhyay, S.
System: The UNT Digital Library
661L Pre Shot Report (open access)

661L Pre Shot Report

None
Date: March 29, 2004
Creator: Bosson, S. T.
System: The UNT Digital Library
The Status of Thermophotovoltaic Energy Conversion Technology at Lockheed Martin Corporation (open access)

The Status of Thermophotovoltaic Energy Conversion Technology at Lockheed Martin Corporation

In a thermophotovoltaic (TPV) energy conversion system, a heated surface radiates in the mid-infrared range onto photocells which are sensitive at these energies. Part of the absorbed energy is converted into electric output. Conversion efficiency is maximized by reducing the absorption of non-convertible energy with some form of spectral control. In a TPV system, many technology options exist. Our development efforts have concentrated on flat-plate geometries with greybody radiators, front surface tandem filters and a multi-chip module (MCM) approach that allows selective fabrication processes to match cell performance. Recently, we discontinued development of GaInAsSb quaternary cell semiconductor material in favor of ternary GaInAs material. In our last publication (Ref. 1), the authors reported conversion efficiencies of about 20% (radiator 950 C, cells 22 C) for small modules (1-4 cm{sup 2}) tested in a prototypic cavity test environment. Recently, we have achieved measured conversion efficiencies of about 12.5% in larger ({approx}100 cm{sup 2}) test arrays. The efficiency reduction in the larger arrays was probably due to quality and variation of the cells as well as non-uniform illumination from the hot radiator to the cold plate. Modules in these tests used GaInAsSb cells with 0.52 eV bandgap and front surface filters for …
Date: July 29, 2004
Creator: Brown, E. J.; Baldasaro, P. F.; Burger, S. R.; Danielson, L. R.; DePoy, D. M.; Dolatowski, J. M. et al.
System: The UNT Digital Library
KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS (open access)

KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

This report covers the second year of this three-year research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict concentrations of all reactants and major product species (H{sub 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the second year of the project we completed the STSR test SB-26203 (275-343 h on stream), which was initiated during the first year of the project, and another STSR test (SB-28603 lasting 341 h). Since the inception of the project we completed 3 STSR tests, and evaluated catalyst under 25 different sets of process conditions. A precipitated iron catalyst obtained from Ruhrchemie AG (Oberhausen-Holten, Germany) was used in all tests. This catalyst was used initially in commercial fixed bed reactors at Sasol in South Africa. Also, during the second year we performed a qualitative analysis of experimental data from all three STSR tests. …
Date: September 29, 2004
Creator: Bukur, Dragomir B.
System: The UNT Digital Library
IMPROVED IRON CATALYSTS FOR SLURRY PHASE FISCHER-TROPSCH SYNTHESIS (open access)

IMPROVED IRON CATALYSTS FOR SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

None
Date: January 29, 2004
Creator: Bukur, Dragomir B.; Carreto-Vazquez, Victor & Ma, Wen-Ping
System: The UNT Digital Library
LIGNITE FUEL ENHANCEMENT (open access)

LIGNITE FUEL ENHANCEMENT

This 1st quarterly Technical Progress Report for the Lignite Fuel Enhancement Project explains what has transpired since Great River Energy was selected to negotiate the Cooperative agreement in February of 2003. The report will summarize Pre-award activities and any other activity since signature of the contract on July 9th of this year. It also summarizes the subsequent purchasing activity and final dryer/process design up to September 30th of 2004.
Date: October 29, 2004
Creator: Bullinger, Charles
System: The UNT Digital Library
Restoring Sustainable Forests on Appalachian Mined Lands for Wood Products, Renewable Energy, Carbon Sequestration, and Other Ecosystems Services Quarterly Report (open access)

Restoring Sustainable Forests on Appalachian Mined Lands for Wood Products, Renewable Energy, Carbon Sequestration, and Other Ecosystems Services Quarterly Report

The overall purpose of this project is to evaluate the biological and economic feasibility of restoring high-quality forests on mined land, and to measure carbon sequestration and wood production benefits that would be achieved from forest restoration procedures. We are currently estimating the acreage of lands in VA, WV, KY, OH, and PA mined under SMCRA and reclaimed to non-forested post-mining land uses that are not currently under active management, and therefore can be considered as available for carbon sequestration. To determine actual sequestration under different forest management scenarios, a field study was installed as a 3 x 3 factorial in a random complete block design with three replications at each of three locations, Ohio, West Virginia, and Virginia. The treatments included three forest types (white pine, hybrid poplar, mixed hardwood) and three silvicultural regimes (competition control, competition control plus tillage, competition control plus tillage plus fertilization). Each individual treatment plot is 0.5 acres. Each block of nine plots requires 4.5 acres, and the complete installation at each site requires 13.5 acres. The plots at all three locations have been installed and the plot corners marked with PVC stakes. GPS coordinates of each plot have been collected. Tree survival, height …
Date: November 29, 2004
Creator: Burger, James A.; Galbraith, J.; Fox, T.; Amacher, G.; Sullivan, J. & Zipper, C.
System: The UNT Digital Library
Advanced Membrane Filtration Technology for Cost Effective Recovery of Fresh Water from Oil & Gas Produced Brine (open access)

Advanced Membrane Filtration Technology for Cost Effective Recovery of Fresh Water from Oil & Gas Produced Brine

Produced water is a major waste generated at the oil and natural gas wells in the state of Texas. This water could be a possible source of new fresh water to meet the growing demands of the state after treatment and purification. Treatment of brine generated in oil fields or produced water with an ultrafiltration membranes were the subject of this thesis. The characterization of ultrafiltration membranes for oil and suspended solids removal of produced water, coupled with the reverse osmosis (RO) desalination of brine were studied on lab size membrane testing equipment and a field size testing unit to test whether a viable membrane system could be used to treat produced water. Oil and suspended solids were evaluated using turbidity and oil in water measurements taken periodically. The research considered the effect of pressure and flow rate on membrane performance of produced water treatment of three commercially available membranes for oily water. The study also analyzed the flux through the membrane and any effect it had on membrane performance. The research showed that an ultrafiltration membrane provided turbidity removal of over 99% and oil removal of 78% for the produced water samples. The results indicated that the ultrafiltration membranes …
Date: September 29, 2004
Creator: Burnett, David B.
System: The UNT Digital Library
FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS (open access)

FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001, ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, AL). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a Compact Hybrid Particulate Collector (COHPAC{trademark}) baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC{trademark} baghouse. Activated carbon was injected between the ESP and COHPAC{trademark} units to collect the mercury. Short-term mercury removal …
Date: January 29, 2004
Creator: Bustard, Jean; Lindsey, Charles; Brignac, Paul; Starns, Travis; Sjostrom, Sharon; Taylor, Trent et al.
System: The UNT Digital Library
Statistical Study of Weight % Insoluble Solids Methods for In-Tank Precipitation Cold Run Support (open access)

Statistical Study of Weight % Insoluble Solids Methods for In-Tank Precipitation Cold Run Support

A statistical study was performed on two candidate methods for measuring the weight percentage insoluble solids in ITP slurry samples. This work was necessary because the preferred method for using a microwave power weight percentage solids analyzer was unsuccessful. The weight percentage solids measurements are needed to provide process control information during the ITP cold runs.
Date: March 29, 2004
Creator: COLEMAN, CHARLES
System: The UNT Digital Library
Biomolecular Simulation Using Amber and CHARMM (open access)

Biomolecular Simulation Using Amber and CHARMM

This project supports the development of software using terascale computers to carry out molecular simulations of protein function and macromolecular interactions. We are building on the existing CHARMM and Amber simulation packages, adapting them in novel ways to massively parallel architectures and high-performance CPUs. Three principal avenues being pursued are: (1) Improvements in load-balancing and communication for large-scale particle-mesh Ewald (PME) simulations of solvated biomolecules. (2) Modern techniques for accelerating convergence of sampling of configuration space offer promise for further exploitation of massively parallel architectures. These methods include parallel tempering and ''lambda dynamics'' procedures that connect multiple, synchronized results from PME simulations like those described in part [1]. (3) The implementation of efficient and scalable algorithms that move towards lower-resolution models in ways that can be carefully calibrated against atomic-level solvated simulations.
Date: November 29, 2004
Creator: Case, David A. & Brooks, Charles L., III
System: The UNT Digital Library
Heat Treatment Procedure Qualification for Steel Castings (open access)

Heat Treatment Procedure Qualification for Steel Castings

Heat treatment practices used by steel foundries have been carefully studied as part of comprehensive heat treatment procedure qualification development trials. These studies highlight the relationships between critical heat treatment process control parameters and heat treatment success. Foundry heat treatment trials to develop heat treatment procedure qualifications have shed light on the relationship between heat treatment theory and current practices. Furnace load time-temperature profiles in steel foundries exhibit significant differences depending on heat treatment equipment, furnace loading practice, and furnace maintenance. Time-temperature profiles of furnace control thermocouples can be very different from the time-temperature profiles observed at the center of casting loads in the furnace. Typical austenitization temperatures and holding times used by steel foundries far exceed what is required for transformation to austenite. Quenching and hardenability concepts were also investigated. Heat treatment procedure qualification (HTPQ) schema to demonstrate heat treatment success and to pre-qualify other alloys and section sizes requiring lesser hardenability have been developed. Tempering success is dependent on both tempering time and temperature. As such, furnace temperature uniformity and control of furnace loading during tempering is critical to obtain the desired mechanical properties. The ramp-up time in the furnace prior to the establishment of steady state heat …
Date: April 29, 2004
Creator: Charles, Mariol; Deskevich, Nicholas; Varkey, Vipin; Voigt, Robert & Wollenburg, Angela
System: The UNT Digital Library
Solid State NMR Measurements for Preliminary Lifetime Assessments in gamma-Irradiated and Thermally Aged Siloxane Elastomers (open access)

Solid State NMR Measurements for Preliminary Lifetime Assessments in gamma-Irradiated and Thermally Aged Siloxane Elastomers

Siloxanes have a wide variety of applications throughout the aerospace industry which take advantage of their exceptional insulating and adhesive properties and general resilience. They also offer a wide range of tailorable engineering properties with changes in composition and filler content. They are, however, subject to degradation in radiatively and thermally harsh environments. We are using solid state nuclear magnetic resonance techniques to investigate changes in network and interfacial structure in siloxane elastomers and their correlations to changes in engineering performance in a series of degraded materials. NMR parameters such as transverse ( T{sub 2}) relaxation times, cross relaxation rates, and residual dipolar coupling constants provide excellent probes of changes crosslink density and motional dynamics of the polymers caused by multi-mechanism degradation. The results of NMR studies on aged siloxanes are being used in conjunction with other mechanical tests to provide insight into component failure and degradation kinetics necessary for preliminary lifetime assessments of these materials as well as into the structure-property relationships of the polymers. NMR and MRI results obtained both from high resolution NMR spectrometers as well as low resolution benchtop NMR screening tools will be presented.
Date: November 29, 2004
Creator: Chinn, S C; Herberg, J L; Sawvel, A M & Maxwell, R S
System: The UNT Digital Library